Evaluation of handling methods in the histological diagnosis of Helicobacter pylori: the effect of filter paper.

Abstract

Few studies have evaluated the handling methods used in the histological diagnosis of Helicobacter pylori. Filter paper has conventionally been used as a receptacle for the biopsy specimen before fixation. The aim of this study was to determine the presence of any effect caused by the use of filter paper. The study population consisted of 104 consecutive patients undergoing endoscopic examination. Two antral biopsy specimens from the same area were obtained from each patient. One specimen was put onto a piece of filter paper, and the other into a plastic case. The specimens were fixed overnight in buffered formalin, embedded in paraffin, sectioned, and stained with hematoxylin and eosin and Giemsa. A direct smear was also prepared from 77 patients by vigorously rubbing the filter paper on a glass slide and staining it with Giemsa. The detection rate of H. pylori was 47.1% (49 of 104) for the filter paper method, 56.7% (59 of 104) for the plastic case method, and 57.7% (60 of 104) for either of the two methods. Of the 60 positive patients, 11 filter paper specimens were negative, whereas only one plastic case specimen was negative. Statistical analysis revealed a significant difference between the two groups (p < 0.01). On the amount of H. pylori, the filter paper method showed a significantly lower grade than the plastic case method (p < 0.05). In the Giemsa-stained smears, H. pylori was identified in 17 (22.1%) of the 77 patients studied. Use of filter paper may decrease the sensitivity for detection of H. pylori infection. We recommend not using filter paper in the histological diagnosis of H. pylori.